基于漏纵波模式的高频宽带低插损滤波器设计  

Design of High Frequency Broadband Low Insertion Loss Filter Based on Longitudinal Leaky Wave

作　　者：王巍[1] 张迎 王方 滕洪菠 丁辉 郭家成 吴浩 WANG Wei;ZHANG Ying;WANG Fang;TENG Hongbo;DING Hui;GUO Jiacheng;WU Hao(School of Optoelectronics Engineering/International Semiconductor College,Chongqing University of Posts and Telecommunications,Chongqing 400065,China)

机构地区：[1]重庆邮电大学光电工程学院/国际半导体学院,重庆400065

出　　处：《压电与声光》2024年第1期1-5,共5页Piezoelectrics & Acoustooptics

摘　　要：采用常规的瑞利声表面波设计低插损、大带宽的高频声表滤波器,难以满足设计要求。该文设计了一种基于多层膜结构的漏纵波(LLSAW)的高频宽带低损耗声表面波(SAW)滤波器。确定了激发LLSAW的波导结构,建立器件的二维理论模型;研究了电极各项参数对杂散的影响,在此基础上对电极参数进行了优化设计。研究发现,将串联谐振器的反射栅对数设置为6时,可有效抑制通带内的杂散。设计了镜像T型及镜像π型LLSAW结构滤波器,并进行性能比较分析。结果表明,镜像T型结构更能抑制杂散响应,设计的镜像T型结构LLSAW滤波器的中心频率为3545 MHz,插入损耗为-1.416 dB,-3 dB带宽为274 MHz,带外抑制大于-30 dB。It is difficult to meet the design requirements of high-frequency surface acoustic wave(SAW)filters with low insertion loss and large bandwidth using conventional Rayleigh surface acoustic wave design.In this paper,a high-frequency broadband low insertion loss longitudinal leaky surface acoustic wave(LLSAW)filter based on multi-layer film structure has been designed.Firstly,the waveguide structure exciting the longitude leaky surface acoustic wave(LLSAW)is determined,and the 2D theoretical model of the device is established.Secondly,the influences of various electrode parameters on the spurious are studied.It is found that when the grating reflector of the series resonator is set to 6,the spurious in the passband can be suppressed as much as possible.Finally,the mirror T-type and mirrorπ-type filters are designed,and the performances are compared.The results show that the mirror T-type structure is more effective in suppressing the spurious response.The designed LLSAW filter with mirror T-type structure has a center frequency of 3545 MHz,insertion loss of-1.416 dB,-3 dB bandwidth of 274 MHz,and out-of-band rejection of greater than-30 dB.

关 键 词：漏纵波 电极 反射栅 杂散响应 镜像T型 

分 类 号：TN65[电子电信—电路与系统] TN713